Ansible vs Terraform Simplified

Published by CyberSec Tutor on

Terraform vs Ansible

Terraform and Ansible are both popular tools used in infrastructure automation

They have distinct purposes and approaches:

Terraform:

  • Focus: Infrastructure as Code (IaC)
  • Purpose: Provisioning and managing infrastructure across various cloud providers and on-premises environments.
  • Configuration: Declarative. You define the desired state of your infrastructure (e.g., VMs, networks, storage) and Terraform orchestrates the creation and management.
  • Configuration Language: HashiCorp Configuration Language (HCL) – Focused on describing infrastructure resources.
  • State Management: Stores the state of your infrastructure (created resources) in a Terraform state file.
  • Mutability: Terraform is primarily for immutable infrastructure. If changes are needed, you modify the configuration and re-run Terraform to recreate the resources with the desired state.

Ansible:

  • Focus: Configuration Management and Automation
  • Purpose: Configure and manage existing infrastructure, including servers, network devices, containers, and applications.
  • Configuration: Declarative or Procedural. You can define the desired configuration state or specific actions to be executed.
  • Configuration Language: YAML (often with Jinja2 templating) – More flexible for complex tasks and conditional logic.
  • State Management: Ansible itself doesn’t maintain a persistent state by default. It relies on idempotent tasks (tasks that produce the same result on every execution) to achieve the desired configuration.
  • Mutability: Ansible excels at mutable infrastructure. You can make changes to existing configurations without necessarily recreating the entire infrastructure.

Here’s a table summarizing the key differences:

FeatureTerraformAnsible
FocusInfrastructure as Code (IaC)Configuration Management and Automation
PurposeProvisioning and managing infrastructureConfigure and manage existing infrastructure
Configuration StyleDeclarativeDeclarative or Procedural
Configuration LanguageHCLYAML (often with Jinja2 templating)
State ManagementStores state in Terraform state filesRelies on idempotent tasks, no persistent state by default
MutabilityPrimarily immutableMore suitable for mutable infrastructure
Terraform vs Ansible

Choosing the Right Tool:

  • Use Terraform when:
    • You need to provision and manage infrastructure across different environments.
    • You prefer a declarative approach for defining the infrastructure state.
    • Immutable infrastructure is desired.
  • Use Ansible when:
    • You need to configure existing infrastructure, including servers, network devices, containers, etc.
    • You prefer flexibility with declarative or procedural configuration options.
    • You need to manage mutable infrastructure and make changes to existing configurations.

Additionally:

  • They can be used together. Terraform can provision the infrastructure, and Ansible can configure the software and applications running on that infrastructure.
  • Other tools like Chef or Puppet offer similar functionalities to Ansible for configuration management.

Image credit

Ansible.com, Public domain, via Wikimedia Commons

Terraform by Hashicorp